As an example, an automated analyzer automatically performs a series of operations of dispensing a predetermined amount of specimen into a reaction vessel, adding a predetermined amount of reagent to the specimen, and then optically measuring the reaction in the reaction vessel by a predetermined measurement section. Various reagents to be added to a specimen are placed by an operator in a predetermined reagent accommodating section of the device, and information about the placed reagents and the placement positions are associated and registered with the device.
Tasks of collecting a specimen from a specimen container and dispensing the specimen into a reaction vessel and of collecting a reagent placed in a reagent accommodating section and dispensing the reagent into the reaction vessel are generally performed by an automated analyzer as described above by using a probe that performs suction and discharge of liquid. In this case, the probe is arranged above a container containing a target specimen or reagent, is lowered to have its tip end placed inside the container to suck in the liquid, and the liquid sucked in is dispensed into the reaction vessel by moving the probe to the position of the reaction vessel.
The automated analyzer described above is sometimes provided with a liquid level sensor for detecting the tip end of the probe coming into contact with the liquid surface, with the aim of preventing pollution of the probe due to the probe being dipped into a specimen or a reagent more than necessary at the time of suction of the specimen or the reagent by the probe (for example, see Patent Document 1). In this case, the outer surface of the probe may be prevented from being polluted by the specimen or the reagent more than necessary, by lowering the probe from above a suction target liquid and detecting the position of the probe at the time of the probe tip end coming into contact with the liquid, and by sucking in the liquid by lowering the probe from the position by only a necessary distance.
Furthermore, the liquid level inside the container may be determined by detecting, by the liquid level sensor, the height of the probe at the time of the probe tip end coming into contact with the liquid, and thus, a function of automatically recognizing the remaining amount of a suction target liquid may be realized.